Modern cataract removal procedures commonly are followed by the implantation of an intraocular lens (IOL) in either the anterior or posterior chamber of the eye. To assist the surgeon typically the implant is made of a foldable, and flexible material. Harder materials have been employed as well. Nonetheless, it is typical that the IOL must be able to be passed through an incision on the order of several millimeters or less, and then be manipulable within the lens capsule for proper positioning.
A typical IOL includes a central lens or optic portion (which replaces the lens of the eye) and a plurality of supporting members, known generally as haptics. Haptics are typically outwardly extending (e.g., radially, tangentially, or the like) structures that are attached to the optic and support the optic within the eye by pressing against adjacent tissue.
In designing IOLs, it is frequently the desire of the designer to provide a haptic structure that permits ready insertion into the lens capsule of the eye and which stabilizes the optic within the eye, helping to prevent undesired lateral, torsional, rotational or twisting and vaulting movement (e.g., with anterior chamber IOLs) within the eye.
The lens capsule of the eye is suspended by fine threadlike zonules. Desirably, implantation of an IOL is accomplished without trauma to the lens capsule or the zonules. For instance, it is common that where inadequate zonular structure is present, an implant than needs to be placed in front of the iris of the eye, or even stitched to the wall of the eye, as recognized by the person skilled in the art.
Examples of IOLs, illustrating various haptic configurations include those described in U.S. Pat. Nos. Des. 395,512; 5,405,386; 5,376,115; 5,306,297; 5,282,855; 5,266,241; 5,047,051; 4,863,539; 4,863,465; 4,842,600; 4,617,023; 4,502,163; 4,468,820; U.S. Des. Pat. Nos. 267,197; and 267,041 hereby incorporated by reference. Several manufactures make a posterior chamber implant (PCIOL) with a single completely enclosed eyelet on each haptic. It is believed, Allergan, Inc., offered an implant with two completely enclosed eyelets on each end of a haptic, which required passage of a suture through the eyelets. The applicant has presented a paper entitled “A Closed-Chamber, Scleral Tunnel Approach to Sutured PCIOLs,” April, 1998 (San Diego, Calif.), in which the applicant disclosed a single partially enclosed eyelet on each of two haptics.